Work feeding device



Aug. '23, 1932. J. M. BACIGALUPI 1,873,922

worm FEEDING DEVICE Filed Jan. 15, 1930 FILE .5

INVENTOR. Jseya/z M Bac/ya/LV w ATTORNEY Patented Aug. 23, 1 932 UNITEDSTATES PATENT OFFICE JOSEPH M. BACIGALUPI, OAKLAND, CALIFORNIA, ASSIGNORTO MARCH ANT CALCU- LATING MACHINE COMPANY, A CORPORATION OF CALIFORNIAWORK FEEDING DEVICE I Application filed January 15, 1930. SerialNo."420,887.

The present invention relates to metal working machinery andparticularly to feeding fingers adapted for use in automatic screwmachines, forming or cutting-off ma-' chines, and the like.

An object of the invention is to provide a bipartite stock feedingdevice in which the stock gripping function is performed by a readilyreplaceable member of nominal cost, andd sized to accommodate the stockto be use Another object of the invention is to providea bipartite stockfeeding device in which the stock gripping function is performed by areplaceable member of relatively soft ma,-

terial, incapable of scratching polished stock,

while thenecessary resiliency for gripping is provided by a secondelement capable of receiving and retaining suflicient. temper.-

Another object of the invention is to provide a stock feeding device inwhich the tempered portion thereof is sufliciently insulated fromfrictionally induced heat to permit retention of its temper. Anotherobject of the invention is to provide a stock feeding device in whichthe part subject to deterioration is capable of replacement at a nominalcost.

Another object of the invention is to provide a device of the aboveattributes or any of them which may be incorporated in modern standardmachines without modification of the machine.

Other objects will appear as the description progresses, reference beinghad to the accompanying drawing in which;

Figure I is an elevation of the auxiliary feeding finger.

Figure 2 shows the auxiliary feeding finger inserted in a standardfeeding fingerand under the compressive spring action of the latter. I

Figure 3 is a longitudinal section through the feeding finger assemblyand a part of the feed tube illustrating the manner in which the stockisgripped.

The form of construction selected for illustration in the presentapplication will be rather specifically described, but it is to beunderstood at the outset, that within the scope of the invention asclaimed, variations may be made.

In the present type of automatic metal working machines, greatdiiiiculty has been experienced in 'finding some satisfactory means offeeding polished stock without scoring and scratching the same. Thestandard feeding fingers now employed are usually made of steel, andcomprise a hollow tubular body member which is threaded at one end forattachment to the stock bar feed tube, while the other end is slotted,slightly tapered, and spring tempered to create a strong compressive orclamping action. Steel, however, has a strong abrasive action on thestock, and when brought into frictional engagement with other stock, hasthe tendency to mark the latter, especially when,

as is frequently the case, burrs are left in the feeding surfaces by themanufacturer. Therefore, when the feed finger is moved rearwardly overthe stock preparatory to gripping and pushing the stock bar forwardly,the latter is badly scored. The only way to overcome this condition,when feeding polished stock, has been to lap the fingers: out at certainintervals to maintain an absolutely. smooth gripping surface. Thisprocedure, however, caused the fingers to wear down much faster andtherefore loose their gripping action, resulting in slippage andinaccurate feeding.

The manufacturers then tried using softer materials such as bronze inthe feeding fingers, but this method also proved unsatisfactory due tothe fact that such metals could not be tempered to provide the necessaryspring tension to. clamp and feed the stock accurately a predetermineddistance. It was be easily inserted in the standard feed mech'- anisnias supplied by the manufacturer.

also found that feeding fingers made of bronze would only last a veryshort time,

necessitating replacements much more often than steel.

Other means have been tried to overcome these great disadvantages infeeding means for polished stock bar, but none seem to have provedsuccessful, mainly for the reason that the improvements required achange in the feeding finger or machine as supplied by the manufacturerswith the result that the manufacturer could not avail himself of this improvement without changing the feeding mechanism entirely, or elseincreasing the sizes and diameter of the entire feeding mechfiIlllSm,including feed tube, collet, and spin- With these drawbacks of, priorstructures in mind, the present invention contemplates as shown in thedrawing, a simple and inexpensive auxiliary feeding finger which canReferring to the drawing which clearly illustrates the auxiliaryfeedingfinger, it can be seen that it comprises a tubular body mem- 7 her 10which is formed out of'a solid round bar of bronze, or similar material,by drilling a central bore 11. It is then counterbored to about threequarters of its length, with the result that the tubular member .10 hasa substantially thicker wall 12 at one end thereof, this end beingselectedto provide the smooth gripping or clamping surface 13 which mustconform to the shape of the stock bar to be fed. In the presentinstance, a round bar is illustrated and hence the surface 13 is annularto correspond to the stock.

This tubular member 10, which constitutes my auxiliary feeding finger,is then turned down on the outside to provide at the other end a narrowshoulder or flange 14, after which it is slotted to approximately itscenter, startingsat the end which carries the gripping surface 13. Theslots 15, created permit it to be compressed upon the stock by theresilient fingers 20 of the main feed finger. Apertures 16 are alsoprovided in the opposite end of the auxiliary feeding finger,

so that when the latter is inserted into the standard feeding finger 17(Figures 2 and 3), these apertures 16, as well as the slots 15, may bealigned with those with which the standard feeding fin er 17 isequipped. The outer surface of tubu ar member 10, of course, conforms tothe inside bore of the standard feeding finger 17, as can be readilyobserved from the drawing. The feeding fin er 17 which is standardequipment of every eeding mechanism for automatic screw machines, etc.,needs'no further description other than that it is made of some goodgrade of steel tubing, has a threaded portion 18 at the end by which itis attached to the feed tube 19 (Figure 3). The other end 20 is slottedexactly like member 10 and is spring tempered, as is well known.Apertures 21 diametrically opposed are provided to allow insertion'of aturn key for screwing the feeding finger onto the feed tube 19.

In practice, when it is desired to work polished stock, the standardfeed finger 17 is removed from the feed tube 19 and the auxiliaryfeeding finger 10 is inserted manually until shoulder 14 abuts the endof the threaded' portion 18 of finger 17. The assembled unit is thenscrewed into the feed tube 19 by in the assembled feed unit, and thespring action of the main feeding finger is imparted to the inserted onewhich therefore is in condition to grip the work stock withs'ufiicientpressure to assure accurate feeding "of the stock at predeterminedintervals, regardless of slightvvariations in the size of the stock.

When the auxiliary feed finger becomes worn bythe passage of stocktherethrough, it

may be easily replaced at nominal cost. The main feed finger, beingrelieved of all wear, and sufliciently insulated from frictionallyinduced heat by the interposed auxiliary finger, will last indefinitely.

I claim: -1. A work feeding device comprising a stock feeding member, afeed tube having means'for securing said member thereon, an adapterinsertible into said member, and means for maintaining said adapter inproper working relation with said member comprising shoulders on saidmember and said tube adapted to grip said adapter.

2. A work feeding device comprising a member having a plurality offingers, an adapter insertible therein provided with a plurality offingers, a feed tube provided with means for securing said memberthereto, means for a igning said member and said adapter durinattachment to said tube comprising aligne apertures in said member andsaid adapter adapted to receive a key, and means for retaining saidmember and said ada ter in alignment after attachment to sai tubecomprising shoulders on said member and said tube adapted togrip saidadapter. v

3. A work feeding device comprising a stock feeding member havingaplurality of fingers, a feed tube provided with means for securing saidmember thereto, an adapter insertible within said member, and means forpreventing longitudinal movement of thd adapter with respect to saidmember and said tube comprising shoulders formed on said adapter andadapted to cooperate vwith shoulders on said member and said tube.

4. A work feeding device comprising a stock feeding member, an adapterinsertlble Within said member, said adapter and said member havingshoulders formed thereon to limit the movement of said adapter uponinsertion within said member, and a feed tube rovided with means forsecuring said memr thereto and a shoulder for holding said adapterWithin said member in assembled position.

JOSEPH M. BACIGALUPI.

